MrSeb writes: "Ever since the release of the iPhone 4 with its 326 pixels-per-inch (PPI) Retina display, people have wondered about the lack of high-PPI desktop displays. The fact is, high-resolution desktop displays do exist, but they're incredibly expensive and usually only used for medical applications. Here, ExtremeTech dives into the world of desktop displays and tries to work out why consumer-oriented desktop displays seem to be stuck at 1920x1080, and whether future technologies like IGZO and OLED might finally spur manufacturers to make reasonably-priced models with a PPI over 100."